Dystonia is a rare complication of acquired immune deficiency syndrome (AIDS). We report four such cases related to three different causes. Cases 1 and 2 both developed dystonia secondary to biopsy-proven progressive multifocal leukoencephalopathy. One had left arm dystonia, whereas the other had bilateral upper limb dystonia. One patient had associated akinesia and rigidity. Imaging demonstrated frontal and/or parietal white matter lesions but no basal ganglia abnormalities. Case 3 developed hemidystonia and cervical dystonia from biopsy-proven toxoplasmosis with a lesion in the thalamus. Case 4 suffered from AIDS dementia complex and developed cervical dystonia while taking risperidone therapy. We also review previously reported cases of dystonia in AIDS patients with the same causes and discuss the issue of increased vulnerability of the basal ganglia to HIV infection which, in turn, leads to increased sensitivity to neuroleptics. When dystonia is seen in AIDS patients, its pattern may be a clue to the ultimate cause.